1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a storage medium storing a control program therefor.
2. Description of the Related Art
Some conventional image processing apparatuses execute an image process to image data stored in memories by units of rectangular areas. For example, an image processing apparatus disclosed in Japanese laid-open patent publication (Kokai) No. 2004-220584 (JP2004-220584A) uses image data in a reference area that is larger than a target rectangular area in order that an image processing unit executes an image process (for example, filtering) to the target rectangular area.
However, the above-mentioned conventional technique needs to read the image data from the reference area that is larger than the target rectangular area in a memory onto which the image data is developed in order that the image processing unit executes the image processing to the target rectangular area. Since the image data stored in the memory is divided into elements of a matrix by the rectangular areas, the reference area overlaps the adjacent rectangular areas around the reference area. Therefore, the image processing unit needs to read the overlapped areas repeatedly during a procedure to execute the image processing to the entire image, which causes a problem of needless consumption of memory band.